1. Field of the Invention
The invention relates to automated storage and dispensing systems for containers, articles and the like. More particularly, the invention relates to systems for storing containers and automatically advancing the containers in the storing apparatus as a container is dispensed from the apparatus.
2. Description of the Relevant Art
Vertically accumulating container storage and retrieval apparatus is shown by Grace, U.S. Pat. No. 4,621,745. This construction consists of opposing stacks of vertically staggered shelves which are pivotable between an upwardly tilted, receiving position, a storage position, and a downwardly tilted, discharge position. Movement of the shelves is controlled such that an upper shelf cannot pivot downwardly to the discharge position unless the next lower shelf is in the upwardly tilted, receiving position. Containers travel down the stack of opposing shelves in zig-zag fashion to come to rest at the lowest unoccupied shelf. Grace, U.S. Pat. No. 5,11,963, discloses a two-position shelf assembly which increases efficiency in some applications. The disclosures of U.S. Pat. No. 4,621,745 and U.S. Pat. No. 5,111,963 are incorporated herein by reference.
There is a continuing need for improved container storage and retrieval apparatus which are adaptable to special situations such as light product weight, variable product weight and heavy product weight. Prior apparatus may not work properly with very light weight containers, which do not have sufficient weight or momentum for mechanical actuation to function properly. Also, very heavy loads may cause jarring, vibration, excessive wear and improper operation.
During operation, a transferred container can topple or lodge between shelf assemblies if the receiving shelf assembly is not prevented from pivoting downwardly from the receiving position before the container is completely disposed on the receiving shelf surface. Accordingly, the descent of the receiving shelf assembly should be delayed until the container is fully received.